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Creep rupture life prediction of high-temperature titanium alloy using cross-material transfer learning

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Journal of Materials Science & Technology 2024年第11期178卷 39-47页

作者： Changlu Zhou Ruihao Yuan Baolong Su Jiangkun Fan Bin Tang pingxiang zhang Jinshan Li State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China Chongqing Innovation Center Northwestern Polytechnical UniversityChongqing 401120China

High-temperature titanium alloys are the key materials for the components in aerospace and their service life depends largely on creep deformation-induced ***,the prediction of creep rupture life remains a challenge due to the lack of available data with well-characterized target ***,we proposed two cross-materials transfer learning(TL)strategies to improve the prediction of creep rupture life of high-temperature titanium *** strategies effectively utilized the knowledge or information encoded in the large dataset(753 samples)of Fe-base,Ni-base,and Co-base superalloys to enhance the surrogate model for small dataset(88 samples)of high-temperature titanium *** first strategy transferred the parameters of the convolutional neural network while the second strategy fused the two *** performances of the TL models were demonstrated on different test datasets with varying sizes outside the training *** TL models improved the predictions greatly compared to the mod-els obtained by straightly applying five commonly employed algorithms on high-temperature titanium *** work may stimulate the use of TL-based models to accurately predict the service properties of structural materials where the available data is small and sparse.

关键词： Machine learning Transfer learning Creep rupture life High-temperature titanium alloy

Phase Evolution Study and Optimization of the Heat Treatment Process for High Current Capacity Bi-2223 Tapes

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Journal of Wuhan University of Technology(Materials Science) 2017年第4期32卷 862-865页

作者：白利锋张胜楠 LI Chengshan HAO Qingbin LIU Guoqing zhang pingxiang The state Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi 'an 710072 China Superconducting Materials' Research Center Northwest Institute for Nonferrous Metal Research Xi 'an 710016 China

Powder in tube process（PIT） was adopted for the fabrication of single filament Bi-2223 tapes, and a heat treatment process including the first heat treatment（HT1）, intermediate rolling（IR）, and second heat treatment（HT2） was performed. The phase evolution mechanism and microstructure changes during these heat treatment processes were systematically discussed. The influences of HT1 parameters on the phase evolution process of Bi-2223 tapes were discussed. With the optimized HT1 process, a proper Bi-2223 content of about 90% was achieved. HT2 process was also optimized by adding a post annealing process. An obvious increase of current capacity was obtained due to the enhancement of intergrain connections. Single filament Bi-2223 tapes with the critical current of Ic-90 A were fabricated with the optimized sintering process.

关键词： high temperature superconductor Bi-2223 phase evolution spray drying critical current density

Supercondcuting properties in MgB2/Fe wires prepared by PIT method

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Chinese Science Bulletin 2003年第13期48卷 1331-1333页

作者： YAN Guo FENG Yong FU Baoquan LIU Chunfang JI Ping zhang pingxiang ZHOU Lian School of Materials and Metallurgy Northeastern UniversityShenyang110004China Supercondluscting Materials Research Center Northwest Institute for Nonferrous Metal Reseanch Xi'an 710016 China

The MgB2 formation was analyzed physically and chemically and the MgB2/Fe wires were fabricated by powder in tube (PIT) technology. The microstructure of MgB2 in wires was studied by the scanning electrical microscope (SEM), which shows a good connection of grains and the size of MgB2 grain is 13 mm. The results of Jc measured by the standard four probes method show that Jc value reaches 6.1?04 A/cm2 at 20 K in self field.

关键词：超导体 MgB2/Fe电线电流密度微观结构扫描电子显微镜

Enhanced superconducting performance in solution-derived YBCO-BaZrO3composite film

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Progress in Natural Science:Materials International 2020年第2期30卷 180-184页

作者： Li Lei Limin Li Xiuting Wang Zhao zhang Gaoyang Zhao Jiqiang Jia Fuxue Yan Zongfan Duan Lihua Jin Chengshan Li pingxiang zhang Advanced Material Analysis and Test Center Xi'an University of Technology School of Material Science and Engineering Xi'an University of Technology Key Laboratory of Electrical Materials and Infiltration Technology of Shaanxi Province Northwest Institute for Nonferrous Metal Research

YBa2Cu3O7-δ/BaZrO3(YBCO/BZO) composite film with enhanced flux-pinning performance was prepared on LaAlO3(LAO) substrate via a fluorine-free sol-gel method in combination with a novel photosensitive sol-gel lithography *** to the difference of lattice mismatch between the interfaces of YBCO/LAO and YBCO/BZO,high-density stacking faults were successfully introduced into YBCO matrix,which has been confirmed by XRD and HRTEM *** measurement results indicate that YBCO/BZO composite film has a stronger current-carrying capacity than the pure YBCO film especially under applied magnetic ***,the critical current density of YBCO/CeO2composite film is much lower than that of the pure YBCO film at all the applied magnetic fields due to the chemical reaction between YBCO and ***,it can be concluded that the flux-pinning performance of YBCO film can be improved by the lattice distortions within YBCO matrix as long as the metal oxide microarrays cannot react with YBCO films.

关键词： Epitaxial growth Sol-gel preparation Superconductors Flux pinning YBCO

Phase evolution mechanism study and fabrication of PbMo_(6)S_(8) superconducting materials with two-step sintering process

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Superconductivity 2023年第1期5卷 40-45页

作者： Botao Shao Lingfeng Ling Shengnan zhang Jixing Liu Lei Zhi Jianqing Feng Chengshan Li Jianfeng Li pingxiang zhang Superconducting Materials Research Center Northwest Institute for Nonferrous Metal ResearchXi’an 710016China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China

PbMo6S 8 superconducting materials are considered to have great potential for practical applications at low temperatures and high fields due to their high upper critical field,low anisotropy,and low preparation *** this work,PbMo_(6)S_(8) bulks were prepared through a solid‐state sintering process using PbS,Mo,and MoS_(2) as raw *** phase evolution mechanism during the sintering of PbMo_(6)S_(8) was studied in *** was found that during sintering at 750℃ for 24 h,both the S and Pb atoms diffuse into the Mo and MoS_(2) particles,leading to the formation of the PbMo_(6)S_(8) *** sintering at 950℃ for 72 h,a high superconducting phase content was obtained in the bulk;however,numerous pores ***,in order to obtain a higher density for the bulk,a two‐step sintering process was *** on this technique,PbMo_(6)S_(8) bulks with a higher bulk density and a higher superconducting phase content were *** study provides an effective method for the fabrication of high‐quality precursor powders,which can be the foundation for the future fabrication of PbMo_(6)S_(8) superconducting long wires or tapes for practical applications.

关键词： PbMo_(6)S_(8) Superconductors Phase evolution Solid‐state sintering

Review of the Research Status of Practical Superconducting Materials and Their Current Carrying Performance

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Chinese Physics Letters 2024年第11期41卷 128-142页

作者： Yifan zhang Shengnan zhang Jixing Liu Fang Yang Chengshan Li Jianfeng Li pingxiang zhang Superconducting Materials Research Center Northwest Institute for Nonferrous Metal ResearchXi’an 710016China School of Material Science and Engineering Northwestern Polytechnical UniversityXi’an 710072China

Superconducting materials hold great potential in high field magnetic applications compared to traditional conductive *** present,practical superconducting materials include low-temperature superconductors such as NbTi and Nb3Sn,high-temperature superconductors such as Bi-2212,Bi-2223,YBCO,iron-based superconductors and *** development of low-temperature superconducting wires started earlier and has now entered the stage of industrialized production,showing obvious advantages in mechanical properties and cost under low temperature and middle-low magnetic ***,due to the insufficient intrinsic superconducting performance,low-temperature superconductors are unable to exhibit excellent performance at high temperature or high *** improvement of supercurrent carrying performance mainly depends on the enhancement of pinning ***-temperature superconductors have greater advantages in high temperature and high field,but many of them are still in the stage of further performance *** high-temperature superconductors are limited by the deficiency in their polycrystalline structure,and further optimization of intergranular connectivity is *** addition,it is also necessary to further enhance their pinning *** numerous successful application instances of high-temperature superconducting wires and tapes also prove their tremendous potential in electric power applications.

关键词： Nb3Sn superconductors performance

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企业项目投资决策净现值法研究

重庆理工大学学报（自然科学） 2020年第2期34卷 252-258页

作者：张萍香福州外语外贸学院财金学院

投资活动是企业财务活动的核心,净现值法是企业项目投资决策的一种基本的评价方法,优于内含报酬率法与获利指数法,更符合企业利润最大化的财务目标。但在执行过程中仍然存在一些不足,如贴现率不好确定,预期现金流量容易与实际发生偏离... 详细信息

投资活动是企业财务活动的核心,净现值法是企业项目投资决策的一种基本的评价方法,优于内含报酬率法与获利指数法,更符合企业利润最大化的财务目标。但在执行过程中仍然存在一些不足,如贴现率不好确定,预期现金流量容易与实际发生偏离及评价指标自身存在的缺陷,针对此提出一些克服净现值法缺点的对策,以利于辅助净现值法,使企业在进行项目投资决策评价时用净现值法能得出正确的结论、选择更好的方案,实现财务管理目标。

关键词：净现值法投资决策贴现率现金流量

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高温超导体材应用进展和展望

稀有金属材料与工程 2000年第5期29卷 293-297页

作者：汪京荣冯勇张平祥西北有色金属研究院西安710016

评述了有关高温超导体材料应用的研究动向 ,着重介绍了高温超导传输和配电电缆、大电流引线、变压器、故障电流限制器、磁共振成像仪磁体、高温超导电机和超导磁性储能等热点项目的优势和国内外进展 ,并讨论了材料产业部门在此形势下。

关键词：高温超导体超导材料超导电缆变压器超导电机

Preparation of Multi-core Bi-2212/Ag Wires

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Preparation of Multi-core Bi-2212/Ag Wires